Inputs

Inputs are the symbols you write on the left-hand-side of a rule diagram to check an atom's surroundings. In the SandPond engine, there are some in-built inputs that you can use straight away:

• @ The centre of the diagram.

• _ An empty space.

• # A non-empty space.

• . Any space.

• * Not a space (ie: the edge of the universe).

• $ This element.

You can also make your own input symbols by using the following keywords:

• symbol

• given

• select

• check